Numerous HIV protein fragments, or peptides, have been identified in an effort to develop an effective HIV vaccine. See generally B. Spalding, Biotechnology 10, 24 (January 1992). Examples of patent applications which are directed to antigenic epitopes of the gp41 protein include J. Rosen et al., PCT Application WO 87/06005 and R. Duncan, EPO Application 0 371 817. To date, the development of an anti-HIV vaccine has been difficult.
N. Qureshi et al., Aids 1990 4, 553-558, describe a segment of the HIV transmembrane protein (designated "gp41") which inhibits T-cell activation in vitro. This segment, designated "CS3", when conjugated to human serum albumin and labeled with fluorescein, binds specifically to CD4+ cell lines, and is said to have antiviral activity. CS3 comprises amino acids 581 to 597 of the gp41 protein.
B. Kemp et al., EPO Application 0 323 157, describes a fragment comprised of amino acids 572 to 591 of the gp41 protein which is said to have antiviral activity.